Myers, just back April 17 from a weeklong trip that included Iraq and Afghanistan, provided firsthand observation into the current situation in Iraq.

"I think what's going on is what we said for some time," Myers told CNN host Wolf Blitzer. "As we get closer and closer, to handing over sovereignty to Iraqis on June 30, the adversary is going to try to interrupt that process.

He mentioned the roles of radical cleric Muqtada al Sadr and al Qaeda associate Muslim extremist and al Qaeda leader Abu Musab al-Zarqawi. "We saw in the Zarqawi's letter four or five weeks ago that he was frustrated that he couldn't make the coalition go away through roadside bombs and all sorts of other attacks," Myers said.

Myers said Zarqawi and al Sadr followers "want to interrupt the progress we've achieved in Iraq and we hope to achieve in the future."

"They'll clearly go to any lengths to do this. As Zarqawi's letter said, 'We're going to have to start a Shiia and Sunni civil war to stop this.'"

That includes hostage taking. "In Fallujah, we think there's pretty good coordination locally between former regime element and Zarqawi followers," he said. "But that's a lot different from the Sadr and his militia, or thugs."

Myer said Sadr has been marginalized, even by other Shiia clerics, who don't approve of what he's doing. "He has been so marginalized that there is not a city under control of his militia as it was about a week ago," Myers noted. "His militia has either melted away or been killed or captured. He's a marginalized individual and right now he's in Najaf, one of the most holy sites of the Shiia world.

"By his preaching, Sadr is not only anti-coalition, he doesn't want progress in Iraq," the general said.

By contrast, Myers said Shiia Grand Ayatollah Ali Husaini Sistani is his own thinker. He noted that Sistani supports the transitional administrative law and the role of the U.N.

As to the cease-fire in Fallujah, Myers said, "The Marines are trying their best to maintain the cease-fire, but they're getting fired upon by these extremists in Fallujah. They are the worst of the worst. They have used women and children as shields, as has Sadr's forces in other parts of the country.

"The leader of the Italian forces near An Nasiriyah said at 5 o'clock in the morning when they're trying to take the city back from Sadr's thugs, out come lots of women and children in front of the fighters," Myers said. "This is not a time when a lot of women and children are on the street. The same tactic is being used in Fallujah."

Myers said interference by Syrians, Iranians or any other country, especially close neighbors, doesn't help what the coalition is trying to accomplish in Iraq and should be stopped.

Blitzer asked Myers about the situation on the Syrian border where five Marines were reportedly killed this weekend. The general said the coalition knows that the pathway into Iraq for many foreign fighters is through Syria.

The Marines are at the Syrian border to interdict "the rat lines," the supply routes foreign fighters are using to travel from neighboring countries into Iraq.

"The Syrians could do more to stop that," he said. "We know that there are the headquarters of various terrorist organizations, such as Hamas, in Damascus.

"The Syrians need to take this situation very seriously. They need to help us stop that infiltration of foreign fighters. It doesn't do their government any good. It certainly doesn't do the work we're trying to accomplish in Iraq any good."

Myers said he wants the Syrians, Iranians and others "to cut off this flow of foreign fighters. I want them to go after the facilitators in Damascus that help these people get the right papers, get the financing or whatever it is they need to get, and the transportation to the border."

If these countries don't comply, Myers said they're going to live with an unstable situation on their border with Iraq longer than would be good.

"I think what's good for them is good for the whole region that is a stable, secure Iraq on path to democracy," he said. "The economic benefits of stability alone would be a huge benefit to the Syrians."

Myers also emphasized that "the U.S. is going to do everything in its power to get Army Pfc. Keith Maupin, 20, and Sgt. Elmer C. Krause, 40, back alive and in good condition."

"That's a basic ethic for the United States military and we'll do all in our power to do that," Myers said.

Both Army Reservists were reported missing April 9, and Maupin was shown on Arab television April 16 as a hostage.